Two stroke cycle internal combustion engine



May 21, 1935.

G. L. STREBLER TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE Filed Aug. 4, 1951 6 Sheets-Sheet l INVENTOR.

May 21, 1935. cs; STREBLER 2,001,935

TWQ-STRQKE CYCLE INTERNAL COMBUSTION ENGINE Filed Aug. 4, 1931 6 Sheets-Sheet 2 N V EN TOR} ORNE May 21, 1935. G. I... STREBLER 2,001,985

TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE Filed Aug. 4, 1931 e Sheets-Sheet 3 INVENTOR.

y 1935- 1.. STREBLER I 2,001,985

TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE Filed Aug. 4 1931 6 Sheets-Sheet 1 INVENTOR: 4713. 5mm):

TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE Filed Aug. 4, 1931 6 Sheets-Sheet 5 Q I L-I m @wm w A m 2 23 an an v 'i r a N N 4-11 Lil IN V EN TOR.

Y W WK T0 NEY.

May'Zl, 1 935.' .G. L. STREBLER 2,001,985

TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE Filed Aug. 4, 1931 6 Sheets-Sheet 6 INVENTOR.

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Patented May 21, 1935 PATENT OFFICE rwo STROKE oYoLE INTERNAL COMBUSTION ENGINE George L. Strebler, St. Louis, 'Mo. Application A-u'g'ust' l, 1931, Serial No. 555,036

7 21 Claims.

This invention relates to improvements in two stroke cycle internal combustion engines, and, has for its object to increase their efliciency.

According to one feature of the invention, each piston has a head at each end; each piston is reciprocal in a one piece cylinder which constitutes a working cylinder at its upper end, and a fuel pumping cylinder at its lower end. A second feature of the invention is in providing each piston with a separable wrist-pin carried intermediate the heads thereof. A third feature of the invention is in connecting each piston with the crank shaft of theengine by means of two connecting rods, the upper ends of each pair of connecting rods being connected with the ends of their respective wrist-pin and the connecting rods being disposed tothe outside of each cylinder wall. A fourth feature of the invention is in providingeach cylinder with 'a fuel transfer cylinder of smaller bore than its engine cylinder to'serve as a manifold between the pumping cylinder and the working cylinder. A fifth feature resides in providing means for admitting fuel from a carbureter to the pumping cylinder. A sixth feature resides in means for admitting compressed fuel from the pumping cylinderto the transfer cylinder.

A seventh feature resides in reciprocati'n means for boosting a fuel charge from the transfer cylinder through a port in the working c'y1 inder wall and a passage in the piston into the working cylinder. An eighth feature resides in means for admitting crankcase air into the pumping cylinder. A ninth feature is in the provision of means for admitting outside atmosphere to the crank case'and'th'en into the pumping cylinder at the end of the upstroke of the piston. A tenth feature of the invention resides in providing a cylinder closed at its lower end as respect to the crank case chamber by the employment of a movable head withinthe lower end of the pumping cylinderso that the area of the pumping cylinder can be varied, as desired. An eleventh feature of the invention resides in the provision of means for raising or lowering the movable head in the lower end of the pumping cylinder. A twelfth feature resides in providing means for oiling the wrist-pin under pressure and in oiling the cylinder wall through the wrist-pin. A thirteenth feature re sides in providing each working cylinder with two spark plugs, the plugs firing alternately with .the alternate upstrokes of the piston, and, a

fourteenth feature resides in the provision of a two stroke cycle internal combustion engine which possesses advantages in points of simplicity and efficiency, and, at the same time proves itself comparatively inexpensive in cost'of manufacture.

With the above and other objects in view, the invention consists the novel features of construction, arrangement and combination of :parts hereinafter more fully described and finally pointed out in the claims hereto appended.

In order thatthis invention may be more clearly understood and readily carried into effect, I will now proceed to describe the same withreference to the accompanying drawings, which illustrate embodiments of this invention and wherein like characters of reference designate like parts throughout the several views, and wherein:-'-

Fig. lis a vertical-sectional view, partly inside elevation of an engine embodying the features of my invention, the engine shown being a four cylinder of the two stroke cycle type, which is equivalent to an eight cylinder engine of the four stroke cycle type.

Fig. 2 is a vertical sectional view, partly in front elevation, showing one of theengine cylinders and its associated parts, the piston being shown in its upstroke position.

Fig. 3 is a vertical sectional view, partly in front elevation, showing oneof the cylinders and its associatedparts, the piston being shown in its downstroke position.

Fig. 4 is'a verticalsectional view, partly in i'SidB elevation, showing two of the engine cylinders and associatedparts.

i Fig. 5 is affront-end elevation ofrthe engine shown in part section. t

Fig. 6 is a rear end elevation of :the engine.

Fig. 7 is a top plan view of the engine shown in part section. i

Fig. '8 is 'a detail of apart of the means shown inpart section. ,7

Fig. 9 'isa vertical sectional view of the .modified form of booster piston for the-fuel transfer cylinders of the engine.

As will be evident to one skilled in the .art, my invention may be adapted to an engine having one, or any numberof cylinders. For the ,purpose of illustration only, I have shown by the drawings an engine having fuel cylinders, which, as is manifest, is equivalent'to eight cylinders in a four stroke cycle internal combustion engine. In the drawings, 1 have designated the four *cylinders, generally as A, B, C and D, but in the detailed description of the engine, the engine parts associated eachcylinder has beendes'ignated with like characters of reference to "avoid primlubricating associated with cylinders B, C and D, as each power unit of the engine is alike in construction, therefore throughout the specification, it will be found that I have used the expression, each cylinder.

The engine, as constructed from the base up, consists of an engine base, or crank case I, to which is bolted, or otherwise secured an oil pan 2. Formed on the base I and depending therefrom are a pair of end main bearings designated 3, and there are intermediate main bearings designated 4 depending from the base I directly below and centrally of each engine cylinder.

A crank shaft 5 is provided with end journals 6 fitting inside the end main bearings 3 and with intermediate journals 1 fitting inside the intermediate main bearings 4. I

Formed on the crank shaft 5 on either side of each intermediate journal 1 are connecting rod journals designated 8 on each of which the lower end 9 of a pair of connecting rods I 8 for each piston are pivoted, thus providing for double connecting rods to each piston of the engine, as will be more apparent hereinafter, so as to more evenly distribute the strains on the crank shaft 5' and also the wrist-pins over a greater bearing surface. Each pair of connecting rods extend upwardly through slotted openings II in the engine base I so as to be disposed to the outside of each engine cylinder and the upper ends I 2 ofeach pair of connecting rods are connected to the ends of their respective wrist-pins designated generally, as E. a

The wrist-pin E for each piston, which pistons are designated generally, as F, and workable in their respective engine cylinder, is separable and consists of two parts designated I3 and M. The part designated I3 is provided with an inner reduced end extension I5 which is externally screw threaded and receivable in a screw threaded bore I6 at the inner end of the other part designated I4, and when thus assembled, constitutes the wrist-pin which is receivable in a transverse bore I1 intermediate the heads of each piston, with the ends of each wrist-pin projecting be-- yond opposite sides of the piston and passing through opposed vertical slotted openings I8 in the wall of each cylinder and fitted in the upper ends of the connecting rods.

7 The upper bored bearing ends of each pair of connecting rods are split, as at I9 so as to be clamped to the ends of their respective wrist-pin by means of a fastening device, such for instance as a bolt 28, thus causing the wrist-pin to rock in its piston bearing with the throw of the crank shaft.

Each engine cylinder is closed at its upper end by a removable engine head 2!, which is held in its fixed position by means of studs 22 carrying the nuts '23. The upper end portions of the cylinders are constructed so as to be provided with water cooling spaces 24, which communicate with a water cooling space 25 inthe engine head 2I. Water connections being old in engines of the internal combustion type, description and illustrations thereof is believed unnecessary. The engine cylinders are preferably case en-bloc and are suitably secured to the engine base plate I. The ends of the engine block are cast open below the water cooling spaces 24 and are closed by means of removable cover plates 26 secured in place by means of suitable fastening devices 21. One side of the engine is also provided with a reing the reference characters designating parts movable cover plate 28 secured in place by means of fastening devices 29.

Each cylinder employed in the engine construction and illustrated as A, B, C and D and regardless of the number of cylinders employed, are each preferably of a single inside diameter throughout their entire length, and each cylinder consists of an upper portion constituting a working cylinder 30 and a lower portion constituting a pumping cylinder 3|.

The piston E for each cylinder consists of an upper portion, or working head 32 fitted with a plurality of suitable rings 33 and a lower portion, or pumping head 34 fitted with a plurality of suitable rings 35. Thus, it will be observed that each piston is a double headed piston workable within a single engine cylinder and owing to the long length of the piston, piston slap is made impossible. The piston for each engine cylinder is preferably hollow, excepting for the wrist-pin bearing 36, and it is internally ribbed, as at 31, to strengthen the same.

A suitable head 38 fitted with a plurality of suitable rings 39 is positioned in the lower end of the pumping end of each engine cylinder. Each head 38 is connected with a suitable shaft 48 by means of a connecting rod 4| and a cam 42. The lower end of the connecting rod is mounted on the cam which is fixed to the shaft 48, and the upper end of the connecting rod is pivoted to a pair of ears 43 depending from the lower end of the head 38, by means of a wrist-pin 44.

The shaft 40 is journaled in bearings 45 and 46 formed in each of the aforesaid intermediate main bearings 4, and the outer end of the shaft 48 extends beyond one of the side faces of the engine base I so that the shaft can be turned to either raise the head 38 through the cam 42 and connecting rod 4| in the pumping cylinder when high compression is desired, or lower the position of the head 38 in the pumping cylinder to lower the compression in the pumping cylinder.

Each engine cylinder is formed on one side with a suitable fuel transfer cylinder G of suitable inside diameter within which is workable a suitable fuel booster piston 41 fitted with suitable rings 48 disposed on opposite sides of a peripheral fuel inlet groove 49, which is disposed intermediate the ends of the piston 41. The upper end 58 of the piston 41, which is in the form of an inverted skirt, is provided on its side facing its respective engine cylinder, with a cutaway portion to serve as a fuel inlet passage to the transfer cylinder from the pumping'cylinder when in register with the port 52 in the wall of the pumping cylinder and the fuel transfer cylinder,'to permit compressed fuel to be forced from the pumping cylinder into the fuel transfer cylinder with the downstroke of the piston in the pumping cylinder. The peripheral fuel inlet groove 49 of the transfer cylinder piston 41, when in register with the fuel inlet port 53 in the wall of the transfer cylinder, also registers with a port 52 and permits fuel from a down draft carbureter, not shown, to pass from an intake manifold 54 into the pumping cylinders during the upstroke of the pistons F working therein. The outlet ends of the intake manifold 54 each feed two pumping cylinders, as will be apparent in Fig. 1.

A suitable drive, or crank shaft 55 is suitably journaled within the crank case chamber adjacent the main crank shaft 5, and is timed to travel at the same speed of rotation as the main crank shaft, and the shaft 55 is connected with each mar transferycylinder piston by means. of a suitable. connecting rod 55; The two crank shafts are connected by means of gears 51 and 58; andintermediate idler gear 58 or an equivalent driving connection. The crank .throw positionsof? the two crank shafts are disposed at approximately right angles to each other with the crank throws of the'crank shaft 40 traveling in advance of the crank. throws of the main crank shaft.

i The wall of each engine cylinder is provided with an inlet. port 59 and with an exhaust port 80', which: latter port is: opposed: to inlet port 591 and. disposed higher" in the cylinder wall with relation to. the inlet port. The piston of each engine cylinder is provided in its working head end=with an L-shaped inlet port 6| which isadapted to register atits lower end with a port 62 in the wall= of each: engine cylinder that communicates. with the upper endof the fuel transfer cylinder. The exhaust port 69 of eachengine cylinderisfully opened when the double headed piston. therein. is. in. its lowermost position, as is thefuel: intake port, but the opening time of each port is not exactly; the same, the exhaust port preferably being opened slightly before the fuel intake. port. In both instances, the. ports are closed by. the sliding movement of the double headed. pistons within the engine cylinders, thus no mechanically actuated valves are employed. I Two spark plugs designatedfiland 64 are employed. with. each engine cylinder and are. carried in. openingsin the engine head so as to be dis-' posed at the top of. each engine cylinder. These plugs are connected'to a. suitable ignition sys-.,

tem, not shown, having .a distributorsoarranged as. to. fire alternately, plug 63 firing to drive the piston down in one stroke, and plug 64 firing to drive the piston down. in its next. stroke, etc.

a In, the modification shown in Fig. 9, the means for'reciprocating the fuel transfercylinder piston compriscs'a. cam Hi fixed to a shaft ll inlieu of the; crank shaft 4'0 shown inFig. 3, and also in- 0.111116% a push rod 12 guided in a. bearingJ'S and av coiled compression spring "interposed between the bearing and a head 15 at the lower end of the push rod 12. The lowerface of the push rod head. (15 is slotted, or recessed, to receive the cam Id to prevent rotation of the push rod and the pistonfixed-thereto. The upper end of the push,

rod I-lis suitably connected with the lower end of the piston 41 which is reciprocable in the .fuel transfer cylinder G. Either the preferred, or modified arrangement for reciprocating the piston in the fuel transfer cylinder ispractical, but the modified arrangement is probably thecheapest. in construction.

Briefly, the operation of the four cylinder engine illustrated, is as follows:

During; the firing, or down stroke of the piston in engine cylinder A, fuel is compressed, which has been previously received in the pumping end of the cylinder and forced into its respective transferpassage, and the charge in the fuel transfer the-main crank throws.

passage is then boosted into the working end of engine cylinder A immediately following the'escape of-burnt, or exhaust gases therefrom to be recompressed with the upstroke of the piston, and fired at the end of the upstroke thereof, there being a fresh charge drawn into the pumping end of the cylinder with the upstroke of the piston. The cycle of operation describedfor cylinder A is the same in all cylinders, and the sequence, or

order of firing. is'determined by the number of.

cylinders employed and the relative positions of The crank; throws associated. with the fuel boosting pistons: reciprocal: in,.the fuel transfer cylinders are identical: inse- .quence, .or order with the main crank shaft. throws, but preferably in ninety-degree advance order of the crank throws of the main. crank shaft. For instance, thefour cylinder engine illustrated, preferably has a firing order, asfollows: cylinder- A being fired first; cylinder B being fired second; cylinder D being fired third and cylinder Cibeing fired fourth, and this order of firing is repeated during the running of the engine.

It is evident, regardless of the number ofengine cylinders employed, that thepistons will bemovedi. downward each. time as a power stroke andv the. spark plugs on each cylinder will be fired alternately; It will be here understood that the fuel; from' the carbureter will be thoroughly intermingled and broken up into. a gaseous state due to the fact that it is, in fact, compressed three times before being fired, first in the pumping cylinder position of each engine cylinder, second in the fuel transfer cylinder associated with each engine cylinder, and, third in the working portion of the engine cylinder. It is further evident that the crank caseis dry and that the bottom of each cylinder is closed to the crank case. Outside air is admitted through inlets 28" and'A' 'to the pump portion of each engine, cylinder and also fumes from the crank case are admitted through the engine base openings H; and the inlet A. to the pumping'cylinders at the end of the upstroke of the pistons in the engine cylinders. The area of the pumping cylinders can be varied and that all bearings, the wrist-pins and the walls of the cylinders are lubricated by a force feed oiling system.

The many advantages of the herein described invention will readily suggest themselves to those skilled in the art to which it appertains.

From the foregoing, it is thought the construction of my engine will be clearly understood and it will be readily appreciated that I have provided an efiicient and substantial engine of the class described, and that while the specification manifests, in detail, the construction of the engine, I do not wish to be understood as having limited myself to the specific details of construction and arrangement of parts as herein described and illustrated, as it is manifest that variations and modifications may be resorted to in the features of construction and arrangement of parts in the adaptation of the engine to various conditions of use without departing from the spirit and scope of the invention. I therefore, reserve the right to all such variations, modifications as properly fall within the scope of my: invention, ashereinafter claimed. I

' What I claim isz' 1.- In an internal combustion engine, an engine cylinder, a. double headed piston reciprocally mounted. in the cylinder, .end closures for the engine cylinder, one of the end closures being removably fixed on the engine cylinder, firing means. carried by said removable end closure and the: other end closure being. carried within. the engine cylinder and adjustable longitudinally thereof to vary the compression: space between; the adjustable end closure. and one head of the piston, means. providing a metallic path to re-- ceive the. initially compressed exploded mixture from the compressionspace at one end'of the engine; cylinder to be delivered to the recomprcss-z ing' and explosiveend of the cylinder, a: recip..-- rocal member in said: path-for, boostingtheinitiallycompressedyexplosive mixture intothe re-i compression and explosive end of the engine cylinder from said path, an inlet port for one end of the engine cylinder, an exhaust port for said end of the cylinder, said ports being opened and closed by the piston, an inlet port for the opposite end of the engine cylinder and an inlet port for the metallic path having timed communication with a down draft carbureter.

, 2. In an internal combustion engine, an initial fresh charge compression chamber, a combustion chamber, a double headed piston separating said chambers, a fuel transfer cylinder, a booster piston arranged for reciprocatory movement within the fuel transfer cylinder, the periphery of the piston being cylindrical in form and tubular at its upper end, an annular groove formed in the periphery of the piston below the upper tubular end thereof providing a fresh charge inlet and transfer passage communication from a source of fresh charge supply to the fresh charge compressionchamber, the wall of the upper tubular end of said piston having a cutaway portion providing an outlet passage communication from the initial fresh charge compression chamber to the fuel transfer cylinder and said piston adapted to boost the initially compressed fresh charge delivered to the fuel transfer cylinder from the compression chamber, into the combustion chamber to be again compressed and fired at the end of the outward stroke of the engine cylinder piston and the combustion chamber having an exhaust port for the discharge of the burnt gases at the end of the inward stroke of the engine cylinder piston which inward stroke of the piston compresses a fresh charge in the compression chamber simultaneously with the boosting of a compressed charge from the fuel transfer cylinder into the combustion chamber.

3. In an intake manifold for internal combustion engines of the two cycle type, a piston valve for reciprocatory movement in the manifold, said valve having an annular groove providing a fresh charge passage communication from a source of fresh charge supply to an initial compression chamber, the upper end of said valve being tubular and having a cutaway wall portion to provide a compressed charge passage communication from the compression chamber to the intake manifold above the piston valve to be boosted by the piston valve into the combustion chamber of the engine wherein it is recompressed and then fired at the end of the upstroke of the piston of the engine and from which combustion chamber the burnt gases are discharged at i the instroke. of the piston approximately simultaneously with the boosting of an initially compressed fresh charge fromthe manifold.

4. In an intake manifold for internal combustion engines of the two cycle type, a cylinder, a double headed piston for reciprocatory movement in the cylinder and forming an initial fresh charge compression chamber at one end and a combustion chamber at the opposite end the piston valve into the combustion chamber of the, engine wherein it is recompressed and then fired at the end of the upstroke of the piston of the engine and from which combustion chamber the burnt gases are discharged at the instroke of the piston approximately simultaneously with theboosting of an initially compressed fresh charge from the manifold.

5. In a two cycle internal combustion engine, the combination with the cylinder and the crank shaft thereof, of a double headed piston arranged for reciprocation in the cylinder and to provide a compression chamber in the lower end of the cylinder and a recompression and combustion chamber in the upper end of the cylinder, two connections between the piston and the crank of the crankshaft, there being a gaseous fuel admission and discharge port formed in the wall of the compression chamber at the clearance part of the compression chamber, an intake manifold integral with the cylinder having a bored chamber and arranged on one side of the cylinder, there being a compressed gaseous fueladmission port in the wall of the recompression and combustion chamber of the cylinder communicating with the upper end of the intake manifold chamber, there being an exhaust port in said combustion chamber, said admission and exhaust ports being controlled by the piston, reciprocating means in the intake manifold chamber, means for admitting gaseous fuel from a source of supply to the compression chamber and also admitting the compressed gaseous fuel from the compression chamber to the intake manifold and said reciprocating means acting as a booster for delivering the compressed gaseous fuel in the intake manifold into the recompression and combustion chamber.

6. In a two stroke cycle internal combustion engine, the combination with an engine cylinder and a doubleheaded piston working therein, of a head fitted with rings in the lower end of said engine cylinder, means for changing the position of the head Within the cylinder, a fuel transfer cylinder associated with the cylinder, fuel ports communicating at opposite ends of the engine cylinder with the fuel transfer cylinder and means mounted in the fuel transfer cylinder for boosting a charge from the transfer cylinder into one end of the engine cylinder.

'7. In-a two stroke cycle internal combustion engine, the combination with an engine cylinder having a double headed piston therein to provide a working cylinder at the upper end thereof having an inlet port and an exhaust port, of a fuel compressing cylinder formed at the lower end thereof having a combined fuel inlet and outlet port, a head fitted with rings adjustably mounted within the lower end of the fuel compressing cylinder, a fuel transfer cylinder disposed alongside the engine cylinder and means for controlling the combined fuel inlet and outlet port of the fuel compressing cylinder.

8. In a two stroke cycle internal combustion engine, the combination with an engine cylinder having a double headed piston therein to provide a working cylinder at the upper end thereof having an inlet port and an exhaust port, of a fuel compressing cylinder formed at the lower end thereof having a combined fuel inlet and outlet port, a head fitted with rings adjustably mounted within the lower end of the fuel compressing cylinder, 2. fuel transfer cylinder disposed alongside the engine cylinder, means for controlling the combined fuel inlet and outlet port of the fuel compressing cylinder and a plunger within the transfer cy'linderto boost a charge therefrom into the working cylinder.

9. In-'a two stroke cycle internahcombustion engine, the combination with an engine cylinder having a charge inlet port and an exhaust port and having a double headed piston working therein controlling said ports and providing for a working cylinder at the upper end of the cylinderand-a fuel compressing cylinder at the :lower end thereof, means for varying the fuel compression space within the compressing cylinder, means for admitting fuel thereinto to be compressed, a fuel transfer cylinder, means for admitting a compressed charge into the transfer cylinder from the compressing cylinder and means for boosting a compressed charge from the transfer cylinder into the working cylinder to 'be fired after-it has again been compressed in the working cylinder. j a

10. In a two stroke cycle internal combustion engine, the combination with an engine cylinder a charge inlet port and an exhaust port and having a double headed piston working therein controlling said ports and providing for a working cylinder at the upper end of the cylinder and a fuel compressing-cylinder at the lower "end thereof, means for varying the fuel compression space within the compressing cylinder, means for admitting fuel thereinto to be compressed, a fuel transfer cylinder, means for admitting a compressed charge {into the transfer cylinder from the compressing cylinder, means for boosting a compressed charge from the transfer cylinder into the workingcylinder to be fired after it has again been compressed. in the working cylinder and means for inducting air into the 'compressingpylinder near the end of the upstroke of the piston within the engine cylinder.

11. In combination with an engine cylinder having a working portion and a pumping portion, of a double headed piston workable in said cyl inder, a head fitted with rings mounted in the lower end of the pumping portion of the engine cylinder, means for moving the position of the head in the lower end of the pumping cylinder to change the area thereof, the wall of the pumping portion of the engine cylinder having a port therein serving both as a fuel inlet and outlet port.

12. In combination with an engine cylinder having a working portion and a pumping portion, of a double headed piston workable in said cylinder, at head fitted with rings mounted in the lower end of the pumping portion of the engine cylinder, means for moving the position of the head in the lower end of the pumping cylinder to change the area thereof, the wall of the pumping portion of the engine cylinder having a port therein serving both as a fuel inlet and outlet port, and said engine cylinder wall also having an auxiliary port therein disposed at a higher elevation than the fuel port serving as an air inlet to the pumping end of the cylinder for admitting air thereinto after having induced a fuel charge thereinto.

13. In combination with an engine cylinder having a Working portion and a pumping portion, of a double headed piston workable in said cylinder, a head fitted with rings mounted in the lower end of the pumping portion of the engine cylinder, means for moving the position of the head in the lower end of the pumping cylinder to change the area thereof, a fuel transfer cylinder integral with the engine cylinder, port communications between the lower end of the pumping cylinder and transfer cylinder, port communication'between the transfer cylinder and the working cylinder, the latter port communication con- 'trollable by the doubleheaded piston, means mounted in the transfer cylinder controlling the port communication between the pumping cylin der and the transfer cylinderandmeans *for boosting a charge admitted from the pumping "cylinder to the working cylinder for inducing it into the working cylinder.-

14. In combination with an engine cylinder having a working portion and a pum'ping pore tion, of a double headed pistohworkable in said. cylinder, a head fitted with'iings mounted in the lower end of the pumping portion of'the engine cylinder; means for 'r'noving the 'position -of the head in the lower end of the pumping cylin'jder to change-the area thereof; a 'fu'el transfer cylinder integral with the enginecylinder, poit communications between the lower end of the pumping cylinder and transfer cylinder, port communication between the transfer cylinder and theworking cylinder, the latter port communication controllable by the =double headed piston, means mounted in the transfer cylinder controlling the port communication between 'the pumping cylinder and'the transfer cylinder, means for boosting a charge admitted from-the pumping cylinder to the workingcylinder farinducing it into the working cylinderand a pair of spark'plugs carried by the head of the 'engine cylinder for alternate firing of the charge delivered to the working cylinder from the transfer'cyli-nder'. 115. In combination with an engine cylinder divided into a working cylinder and a fuel pumplng cylinder. bythe employment; of a double -headed piston reciprocally fmounted therein, means for-changing thearea of the p'u rn plng cylinder, 'afuel transfer cylinder, means for admitting fuel into the pumping cylinder to be compressed therein, means for admitting the compressed fuel from the pumping cylinder into the transfer cylinder, means for boosting the compressed charge in the transfer cylinder into the working cylinder and therein to be again compressed by the double headed piston.

16. In combination with an engine cylinder divided into a working cylinder and a fuel pumping cylinder by the employment of a double headed piston reciprocally mounted therein, means for changing the area of the pumping cylinder, a fuel transfer cylinder, means for admitting fuel into the pumping cylinder to be compressed therein, means for admitting the compressed fuel from the pumping cylinder into the transfer cylinder, means for boosting the compressed charge in the transfer cylinder into the working cylinder and therein to be again compressed by the double headed piston, and two spark plugs carried by the head of the engine cylinder at the working end thereof, said spark plugs adapted to be fired alternately for igniting alternate charges in the working cylinder.

17. In an internal combustion engine of the class described, an engine cylinder, a double headed piston reciprocally mounted in the engine cylinder and dividing the cylinder into a working cylinder at one end and a fuel pumping cylinder at the opposite end, the wall of said working cylinder having an exhaust port therein, aninlet port in the working head end of the piston, a fuel transfer cylinder disposed in parallel relation with the engine cylinder, a port in communication with the pumping cylinder and 18. In an internal combustion engine of the .class described, a working cylinder, a fuel pumping cylinder integral therewith, ,a double headed piston working in'said cylinders, a fuel transfer cylinder integral with the working and pumping cylinders, a piston valve working in said transfer cylinder, means for admitting a charge from a source of supply to the pumping cylinder, means for admitting the charge from the pumping cylinder'to the transfer cylinder under pressure, means for discharging the compressed charge from the transfer cylinder to the work- 'ingcylinder wherein it is recompressed before it is fired and means for' firing the-charge in the working cylinder;

l9. In an internal combustion engine of the class described, a working cylinder, a fuel pumping cylinder, integral therewith, a double headed piston working in said cylinders, means within the pumping cylinder whereby the area thereof can be changed, a fuel transfer cylinder integral with the working and pumping cylinders, a piston valve working in said transfer cylinder, means for admitting a charge from a source of supply to the pumping cylinder, means for admitting'the charge from the pumping cylinder to thetransfer cylinder under pressure, means for discharging the compressed charge from the transfer cylinder to the working cylinder wherein it is recompressed beforeit is fired and means for firing the charge in the working cylinder.

20. In an internal combustion engine of the class described, a working cylinder, a fuel pumping cylinder integral therewith, a double headed piston working in said cylinders, a head fitted with rings disposed in the lower end of the pumping cylinder, means for raising and lowering the position of the head in the pumping cylinder, a fuel transfer cylinder integral with the working and pumping cylinders, a piston valve working in said transfer cylinder, means for admitting a charge from a source of supply to the pumping cylinder, means for admitting the charge from the pumping cylinder to the transfer cylinder under pressure, means for discharging the compressed charge from the transfer cylinder to the working cylinder wherein it is recompressed before it is fired and means for firing the charge in the working cylinder.

21. In combination with an engine cylinder having an inlet port and an outlet port, of a double headed piston in said cylinder forming the cylinder into a Working cylinder and fuel pumping cylinder and said piston controlling saidinlet and exhaust ports, a head in the pumping cylinder, means for movably supporting said head, a fuel transfer cylinder, a port connection between the compression clearance end of thepumping cylinder and the fuel transfer cylinder, means permitting the introducing of a fuel charge from a source of supply into the pumping cylinder wherein it is compressed, means for permitting the compressed charge to be introduced into the transfer cylinder and means for boosting the compressed charge in the transfer cylinder into the working cylinder wherein it is recompressed and means for firing the charge in the working chamber.

GEORGE L. STREBLER. 

